Unit die assembly



May 26, 1964 H. M. CANNER UNIT DIE ASSEMBLY 5 Sheets-Sheet l Filed May 31, 1961 BY )fami/*aafla ATTORNEYS May 26, 1964 H. M. CANNER 3,134,142

UNIT DIE ASSEMBLY Filed May 31, 1961 3 Sheets-Sheet 2 INVENTOR. HERMAN M. CANNen AT TORNEYS May 26, 1964 H. M. cANNl-:R

UNIT DIE ASSEMBLY 3 Sheets-Sheet 3 Filed May 3l, 1961 m .om

INVENTOR. HERMAN M. CANNe-.R

ATTORNEYS United States Patent Oiice 3,134,142 Patented May 26, 1964 3,134,142 UNIT DIE ASSEMBLY Herman M. Cannet, 261 E. Goldengate, Detroit 3, Mich. Filed May 31, 1961, Ser. No. 113,693 12 Claims. (Cl. 18-42) This invention relates to injection die molds and has particularly to do with that type of mold which is utilized for molten zinc or aluminum. It is equally adaptable to a plastic molding operation.

It is an object of the invention to provide a die unit which can accommodate different mold cavities and which has a simple and effective device for locking the respective mold cavity plates in position in the die actuating mechanism.

It is another object to provide a die mechanism with ejector pins which can be assembled with ejector plates and utilizing support pillars under the units.

It it a further object to provide a device with an accelerated ejector pin feature for use in automatic die casting.

It is a further object to provide a device in which the ejector plate and the core retainer plate can be assembled simultaneously and readily locked in position.

Other features and objects of the invention relating to details of construction and operation will be apparent in the following description and claims.

Drawings accompany the disclosure and the various views thereof may be briey described as:

FIGURE l is a side elevation of the device partially in section showing the relationship of the assembled parts.

FIGURE 2 is a View of the ejector plate unit in perspective.

FIGURE 3 is a view of a .core retainer plate in perspective in a position relative to the plate of FIGURE 2.

FIGURE 4 is an end View of the device partially in section showing ejector pins and accelerating mechanism thereof.

FIGURE 5 is a partial end view showing the die in open position.

Referring to the drawings:

The machine has a base plate with a longitudinally extending rack bar 22 between the sides, this bar cooperating with a plurality of elongate pinion rods 24 to control the vertical movement of actuator posts 26. There are six of these rack posts 26, two at the center area of the device, and two at each end to act on a lifter plate which is described later. These posts are preferably secured directly to the lifter plate by suitable screws.

One of the elongate pinion rods 24, such as the middle one, can serve as the actuator for the rack bar which causes a lifting of the ejector plates at the proper sequence in the operation. On the base 20 is mounted a channel shaped body member 28 having side walls 30 and 32 (FIGURE 4) and a bottom wall 34.

Within this channel-shaped member and mounted on the six rack posts 26 which are actuated by the pinion rods 24 is a H-shaped lifter plate which has a cross bar portion 36 shown in section in FIGURE l and arms 38 extending in each direction from this cross bar plate to the end of the channel and located adjacent the inner sides of the channel 30. On the top of the cross bar 36 of the H plate is a pin mounting bar 40 having recessed sides to provide transverse grooves 42 facing outwardly. On the plate 40 will be mounted permanently sprue ejector pins 44 of standard construction.

A center portion of the mold containing the sprue comprises a lower sprue bar or block 50 bridging the two side walls 30, 32 of the member 28 and supported on the top edges thereof at the center. A parallel plate 52 on this bridging block lies between the side walls 30 and 32 transversely of the assembly and centrally thereof. This block 52 contains two fixed pins 54 and 56 which cooperate with an accelerator device which is mounted in the plate 40. This device comprises jack levers 58 and 60 pivoted centrally on pins 62 in recesses 64 at opposite ends of the plate 40. Resting on a toe portion of the inner end of the levers 58 and 60 is an accelerator ejector pin 66, this pin having a slidable mounting in plate 52 and block 50 projecting upwardly to the sprue portion of the mold recess 68.

As will be seen from FIGURE 4 and FIGURE 5, a lifting of the plate 40 will cause a lifting action of the sprue pins 44 as well as the pin 66, and, at a certain stage in the lifting motion, the heel end of the levers 5S and 60 will contact the depending pins 54 and 56, thus doubling the rate of lifting of the pins 66 for the purpose of rapidly increasing the eject force on the sprue portion of the mold to cause a snapping out of the part from the mold.

Above the lower sprue bar block 50 is a second transverse block forming an upper sprue bar '70 having suitable guide pins 71 to locate it slidably relative to the block 50, this block 70 containing a sprue opening 72 for the entrance of molten material.

The above-described mechanism might be called the unit die which is ready to receive the special die cavities for any particular product. It will be noted that between the lower surface of plate and the top surface of the bottom 34 of the channel-shaped body there is a considerable space. It will be noted that ends of the arms 38 of the H member are undercut at 82. Similarly, notches 84 are cut into the end faces of the sides 3i) and 32 spaced from the top edge on each side and also the top ends of the plate 80 are beveled at 86 to provide a gripping surface for a purpose to be later described.

Insertable into the recesses described in 'connection with `the unit die are the'die plates and also a combination ejector plate and a core retainer plate. It will be understood that the ejector plate and the core retainer plate must be moved in together since the core pin is inserted into the support pillar and similarly the pins of both plates must lie in proper position in the bottom die before insertion. Consequently, the assembly consists of a core pin plate or core retainer plate and a core pin 92 (FIG- URE 3) and an ejector plate 94 having, for example, four ejector pins 96 and a support pillar 98 which receives the core pin 92. All of these pins project into a lower die block 100.

Before describing the assembly, it should be pointed out that retainer bars 102 having an undercut recess 104 are mounted in the bright of each H member of plate 36 and anchored to the bottom 34 of the channel member 30 (FIG. 1, FIG. 4).

In the assembly of plates 90, 94 and 100 the pins and the cores are telescoped together outside the die unit. Then the entire three plates are moved endwise into the cavity of the die unit. The forward edge of plate 94 moves into the recess 42 of plate 40. The leading edge of the core plate 90 moves into the recess 104 under the bars 102. At the trailing edge of the plate 90 is a L-shaped bracket member 106 which has a toe portion 108 which locks under the end of the plate 40.

The lower die cavity block overlies and bridges the channel sides 30, 32 and the forward edge of the cavity block 100 has a recess which registers with a pin 110 to lock it in place relative to block 50. A clamping yoke or tie block 112 having toe portions 114 and 116 is then applied to engage the notch 84 in wall 30 and to engage a notch 118 in block 100. Screws 120 when tightened secure the block 100 to the base. The trailing corner of the plate 94 are also provided with locking brackets 122 having a toe portion 124 which engages in recess 82 vin the die block 130 and a foot 140 engaging the surface 86 previously described on plate S0. The block 100 has a die cavity 150 on its upper surface in which the product is manufactured, this cavity being connected through suitable sprue passages to the sprue opening 72 in the top of the plate 80.

In the operation of the device when assembled as above described, it will be seen that with the parts as viewed in FIGURE 1 or FIGURE 4 the assembly is ready for a die casting in which molten material is either poured or injected into the opening 72. When it is desired toeject the molded product, the pinion rod 24 is actuated tolift the H plate 36 with its center bar 36 and its outwardly extending legs 38 through the rack and post supports. The core plate 9) with the core pin 92 remains stationary but the tin plate 94 raises with the lifting plate as does also the block 70 and the upper die cavity blocks 130 with the supporting plate 8f). The pins 66 act not only on a portion of the sprue passages but also on the bottom surfaces of the plate '70, thus lifting the upper assembly. At the same time, the pins 96 exert upward force on the product in the die cavity. As the upward motion continues, as previously explained, the lifting pins 66 contact at the heel and the pins 54 and 56 and thus the upper plate and the center portion of the sprues begins to move more rapidly in an upper direction than the pins 96. This tends to` give an added acceleration to the sprue relative to the product which exerts a force on the product to strip out the molded product permitting it to fall out of the lower die cavity or to be easily retrieved from the cavity. A stop pin 160 on plate 40 limits the upward motion of the lifter plate. It will also be seen that because of the use of the single lifter plate which is simultaneously elevated at several different points, the wracking of the mold is prevented.

It will thus be seen that there is described a unit die assembly which can be readily adapted to dierent die cavity blocks and at the same time being so designed that the cavity blocks may be assembled simultaneously with the core plate and the stripper pin plate which in connection with the accelerated central pin action provides auto'- matic ejection. In addition, the device is so constructed that the assembled parts are securely and simply held in position for ready removal in a fast dismantling operation and a ready assembly for a new operation with different die blocks. It will be seen that the device described is provided with a double cavity but it could equally well be a single cavity die or have other multiple cavities.

While in the disclosure and the claims reference is made to base and top in vertical relationship, it will be recognized that the entire device could be turned 90 to operate in a horizontal relation if desired.

I claim:

1. A unit die combination comprising a base, a bottom spruce bar rigidly mounted on said base, an upper sprue bar slidably mounted with respect to said bottom sprue bar, a top plate on said upper sprue bar overlying said base, said base and said top plate delining a laterally exposed opening, a lifter plate, means for mounting said lifter plate on said base for movement in direction perpendicular to the base and to the top plate, said lifter plate having a central portion carrying sprue ejector pins and lifter pins for said upper sprue bar, upper die cavity blocks mounted on the lower surface of said top plate, and a lower die cavity assembly comprising a lower die cavity block, a core plate and an ejector pin plate movable as a sub-assembly endwise into said opening between said base and said top plate below said top cavity bars, and means operable to lock said core plate and said ejector pin plate in position in spaced relation upon endwise movement into said die unit, said ejector pin plate being thus engaged with said lifter plate to operate simultaneously therewith.

2. A device as defined in claim l in which the base comprises a channel-shaped body member having longitudinally extending side walls, and a lower sprue plate bridging said side walls serving as a support for said top plate.

3. A device as defined in claim 2 in which a sprue pin plate underlies said bridging member, and pins are mounted on said plate extending into said bridging member for removing sprue portions of a mold upon relative movement between said top plate and said base.

4. A device as defined in claim l in which the means operable to lock said core plate and said ejector pin plate comprises undercut recesses in said base and said lifter respectively to receive the leading edges of said plates and hook means on the trailing edges of said plates to engage the base and the lifter plate respectively, said core plate then being fixed to said base and said ejection plate being fixed to said lifter plate.

5. A device as defined in claim 1 in which the upper and lower die cavity blocks are secured to the base and the top plate by tie bars having wedging toe portions to lock said parts securely while mounting said core plate and said ejector pin plate in locked position.

6. A device as dened in claim 1 in which the base comprises a channel shaped body, the lower die cavity block overlying and bridging the sides of said channel, the core plate being iixedly positioned between said sides adjacent the bottom of the channel, the ejector pin plate lying also between the sides of said channel affixed to said lifter plate.

7. A device as defined in claim 6 in which the lifter plate has spaced legs to receive the core plate on the base and the ejector pin plate overlies and bridges said legs.

8. A unit die mechanism for injection molding and casting which comprises a base, a bottom sprue bar on said base spaced upwardly from the bottom thereof, a lifter plate on said base between said sprue bar and the bottom of said base, a top plate and upper sprue bar on said top plate overlying said bottom sprue bar, said top plate overlying said base, means between said base and said top plate adjacent said sprue bars for mounting upper and lower die cavities affixed respectively to the base and the top plate, and means for elevating said lifter plate comprising a plurality of rack posts operatively associated with said lifter plate at spaced points in its geometric area, a plurality of pinion rods associating said rack posts in pairs transversely of said plate and means operatively connecting said pinion rods to cause simultaneous operations of said rods when any one of them is actuated wherein actuation of any of said pinion rods causes an equal and simultaneous actuation of all of said rods and said pinion posts and thus a plurality of simultaneous lifting forces on said lifter plate.

9. A device as defined in claim 8 in which the means associating said pinion rods comprise a straight, toothed rack slidably mounted in said base and engaged with the said pinion rods.

10. A device as defined in claim 8 in which the lifter plate comprises a plate having spaced parallel arms, and said rack posts are associated with the digital and proximal ends of said arms to create an equal lifting force thereon.

11. A device as defined in claim l() in which the arms of said lifter plate are projecting toward the end of said die unit, and an ejector pin plate mounted on said arms having pins projecting upwardly to pass through a lower die cavity to serve as ejector pins for a workpiece.

12. A unit die combination comprising a base, a bottom sprue bar rigidly mounted on said base, an upper sprue bar slidably mounted with respect to said bottom sprue bar, a top plate on said upper sprue bar overlying said base, said base and top plate defining an opening therebetween, a lifter plate, means for mounting said lifter plate on said base for movement in direction perpendicular to the base and to the top plate, said lifter plate having a central portion carrying sprue ejector pins, an upper die cavity block mounted on the lower surface of said top plate, and a lower die cavity assembly comprising a lower die cavity block, a core plate and an ejector pin plate movable as a subassembly into said opening between said base and said top plate, and means operable to lock said core plate and said ejector pin plate in position in spaced relation, said ejector pin plate being thus engaged with said lifter plate to operate simultaneously therewith, and means for accelerating the movement of 15 References Cited in the tile of this patent UNITED STATES PATENTS 2,446,872 Ehlers Aug. 10, 1948 2,783,501 Kutk Mar. 5, 1957 FOREIGN PATENTS 1,178,357 France May 6, 1959 OTHER REFERENCES Modern Plastics, page 68, March 1942, l8-305. 

12. A UNIT DIE COMBINATION COMPRISING A BASE, A BOTTOM SPRUE BAR RIGIDLY MOUNTED ON SAID BASE, AN UPPER SPRUE BAR SLIDABLY MOUNTED WITH RESPECT TO SAID BOTTOM SPRUE BAR, A TOP PLATE ON SAID UPPER SPRUE BAR OVERLYING SAID BASE, SAID BASE AND TOP PLATE DEFINING AN OPENING THEREBETWEEN, A LIFTER PLATE, MEANS FOR MOUNTING SAID LIFTER PLATE ON SAID BASE FOR MOVEMENT IN DIRECTION PERPENDICULAR TO THE BASE AND TO THE TOP PLATE, SAID LIFTER PLATE HAVING A CENTRAL PORTION CARRYING SPRUE EJECTOR PINS, AN UPPER DIE CAVITY BLOCK MOUNTED ON THE LOWER SURFACE OF SAID TOP PLATE, AND A LOWER DIE CAVITY ASSEMBLY COMPRISING A LOWER DIE CAVITY BLOCK, A CORE PLATE AND AN EJECTOR PIN PLATE MOVABLE AS A SUB-ASSEMBLY INTO SAID OPENING BETWEEN SAID BASE AND SAID TOP PLATE, AND MEANS OPERABLE TO LOCK SAID CORE PLATE AND SAID EJECTOR PIN PLATE IN POSITION IN SPACED RELATION, SAID EJECTOR PIN PLATE BEING THUS ENGAGED WITH SAID LIFTER PLATE TO OPERATE SIMULTANEOUSLY THEREWITH, AND MEANS FOR ACCELERATING THE MOVEMENT OF AT LEAST ONE OF SAID EJECTOR PINS RELATIVE TO SAID LIFTER PLATE AFTER A PREDETERMINED MOVEMENT OF SAID LIFTER PLATE TO INCREASE THE LIFTING RATE OF SAID ONE EJECTOR PIN ABOVE THAT OF THE PLATE. 